In a programme of pioneering research at Edinburgh University, Dr Jim Wilson has been gathering samples of DNA from Scots across the country and this week, • Somerled, the first Lord of the Isles

in a new book by Alistair Moffat, and in a series of
features in The Scotsman, we discover what his innovative work has revealed – and where the Scots came from. DNA – deoxyribonucleic
acid – is the basis of life. Its molecular structure was discovered in 1953, revealing how it carries all the genetic information needed for organisms to live and reproduce. Scientists describe it in sequences of letters, and humans inherit three billion from each
of their parents. As generations move from place to place, distinctive DNA markers are carried by each and every one of us. Day 2 of
our series looks at the men who have literally left their mark on history

MORE than 16 million men, 0.5 per cent of all men on Earth, are the direct lineal descendants of one man. When a survey of the genealogy of 2,000 men was completed, researchers were astonished to find a large proportion were very closely related. They shared the same DNA marker.

This is the term attached to the very slight differences in our DNA, and people with the same marker are related. In a survey on this scale occasional clusters of relatives are sometimes found, but what surprised researchers was the huge number of near-identical markers. Nothing like it had ever been seen before.

More than 8 per cent of the entire sample, taken across 16 populations in a huge geographical area from central Asia to the Pacific coasts, carried the same marker. It was possible to date its origin to about 1,000 years ago. The second highest frequency of the marker and the place where its internal diversity was greatest turned out to be Mongolia, clearly the place it originated. The lineage is unique and it is unquestionably the case that 8 per cent of all men from Uzbekistan to Manchuria are descended from one individual. And outside this area, there are no men carrying this marker. Something remarkable has happened in the past. Who was this extraordinary Adam-figure, the father of several nations?

Over only 34 generations, this pattern of reproduction is beyond anything seen in nature amongst animals as a result of natural selection. Statistical calculations rule out chance as an explanation.
It must be the case that not only has a dramatically sustained streak of the reproductive fitness of men with this marker been observed, there must have been large-scale elimination of other Y chromosome lineages going on at the same time. There can be only one candidate for the progenitor of 16 million men in central Asia, 0.5 per cent of all men on the planet: the great warlord, Genghis Khan.

He lived between c1162 and 1227 and he and his sons and grandsons created the largest land empire in history, often slaughtering the conquered populations as his horse-riding hordes thundered across the plains and attacked cities and other tribes. The boundary of the Mongol Empire at its fullest extent is almost exactly matched by the frequency of his marker.

Much closer to Scotland was a man who died when the great Khan was born. His exertions bore a good deal less fruit, but then he operated in a much smaller area on the edges of Europe. More than 20,000 Scottish men, most of them with the surname MacDonald or its variants, are the direct descendants of Somerled. The first Lord of the Isles and founder of Clan Donald, he ruled the Hebrides and was King of the Isle of Man. When he clashed with Malcolm IV of Scotland at Renfrew, Somerled was killed in 1164 – but his genes lived on.

The alleged medieval tradition of droit de seigneur– the right of a local lord to have sex with any new bride in the community he controlled – was also known as the ius primae noctis, or the right of the first night. The idea that a lord might be powerful enough to insist that he should deflower a bride before her husband has long been hypothesised. But DNA studies suggest it did go on. While it is unlikely that seigneurs exercised their droit in quite that way, with each new bride, it is certain that they had productive sex with many women. This phenomenon could have attracted a racy label, but scientists simply and soberly call it social selection. And in Britain and Ireland it had profound effects still observable today.

An old lineage dating from AD400 to AD500 has been recently identified in Ireland. Known as M222, it is astonishingly common. No less than 20 per cent of all Irish men carry it. Its distribution is heavily weighted to the north, with 40 per cent in Ulster, 30 per cent in Connaught and 10-15 per cent in Munster and Leinster.

No less than a fifth of all Irish men are directly descended from one man who lived around 1,500 years ago. Given the distribution of the marker and its bias to Ulster and especially to men with the O’Neill and O’Donnell surnames, there exists a clear candidate. The Ui Neill kindred dominated Irish history from the 5th to the 10th centuries and their founder was the High King known as Niall Noigiallach. His political reach is reflected in his second name for Niogiallach means “of the Nine Hostages”. These were the sons of lesser kings who owed Niall obedience and they were kept in his retinue as a guarantee of continued compliance.

The simple reality is that Niall fathered many sons by many women, and those sons, themselves growing up to be powerful men, followed the same pattern. The first High King’s reign and his exploits are shrouded in mist and mystery, but in the historic period one of his ancestors showed how it was done, so to speak. Lord Turlough O’Donnell, who died in 1423, carried on the family tradition with gusto. He had 14 sons and 59 male grandchildren. From this example alone it is easy to see how a marker multiplied very quickly. If the same level of enthusiasm and fertility was sustained, Lord Turlough would have had 248 great grandsons and 1,040 great, great grandsons. Within only four generations, and without taking any account of bastards, he could have bred an army. These examples and a growing body of evidence for social selection tend to lend weight to some of the more extravagant claims of the genealogy industry. Every second person who has their DNA analysed seems to be convinced that they descend from royalty or the more glamorous aristocracy. Perhaps this is not misplaced after all.

More generally, the incidence of M222, the marker of Niall Noigiallach, in Scotland is very interesting. Generations of historians have been unable to agree about the earliest history of the kingdom of the Scots. It sprang from Dalriada, the Argyll kingdom ruled by Gaelic speakers and which originally had territories on both shores of the North Channel. But historians have been recently disposed to believe that the spread of its power and the Gaelic language were a process and not the consequence of an event, like an invasion. M222 suggests otherwise. The marker is very widespread in Scotland with 6 per cent of all Scottish men carrying it, around 150,000. It seems that around AD500 many Irish men crossed the North Channel and did not return. Perhaps not a D-Day style invasion, but certainly a very significant influx and a takeover.
The traditional claims of several of the older clans of Argyll and the south-western highlands and islands may have more substance than mere myth or wish-history. Clan Campbell also call themselves Siol Diarmaid, the Seed of Diarmaid and Irish origins are also included in the uncertain, early histories of Clans Lamont, MacInnes and MacDowall and others. More than affinity or geography is at work here.

The workings of social selection and what it says about the status of women in history may seem more than faintly shocking. Gender equality may remain an unwon cause in the 21st century but the advances made in the last few generations have been immense. For much of recorded western European history, from the Romans to the Victorians, women have had the status of children, or worse. The biographer of St Columba, St Adomnan, promulgated what became known as the Law of the Innocents (to protect women, children and the church from the effects of warfare) and in his writings he talked of women as “little slaves”.

DNA studies may appear to reinforce this picture of gender inequality. Much of the most striking material in The Scots: A Genetic Journey is derived from studies of Y chromosome DNA, and it is an unhappy imbalance. But there are good scientific reasons for it. Throughout history men tended to stay where they were born and raised, while women tended to move, probably not willingly. Property passed down the male line and that anchored men in a particular locality, and gave their lineage a history there. The workings of social selection also encouraged men not to move. In an age when numbers mattered, a property owner (even a modest one) who had many sons and grandsons was a more powerful man. The fecundity and energy of Lord Turlough O’Donnell in the turmoil of late 14th and early 15th century Ireland was not only a matter of macho pleasure and pride, it also made military sense. What these historical factors mean is that Y chromosome DNA is often traceable to a particular place, somewhere that can be identified as the origin of a marker.

Women, by contrast, were probably moved on as marriage partners, and over generations, many will have been further and further removed from their mothers, grandmothers, great grandmothers and so on. Women were also undoubtedly traded as human commodities and as outright slaves. This has meant that mitochondrial DNA, what mothers pass on through their daughters, has become very dispersed and difficult to track in detail.

Nevertheless, DNA studies strongly suggest a pivotal role for women in the greatest revolution in world history. Farming began in the Fertile Crescent, the lands between the rivers Tigris and Euphrates, around 9,000BC. In addition to gathering a wild harvest of fruits, roots, nuts and berries, people began to domesticate wild grasses, slowly turning them into cereal crops.

Docile, sociable, manageable and meaty animals were also domesticated and as farming techniques and ideas spread, populations began to mushroom and people and ideas began moving. By 5,500BC there were farms in the Danube Valley and the revolution soon penetrated the heart of Europe and the plains to the north. Having cleared woodland and scrub, communities sometimes built a particular style of longhouse, and to store and cook what they grew, the new farmers made a new pottery. Known in German as Linearbandkeramik, or LBK, it was decorated by lines incised into the clay before firing.

In 1976 in Aberdeenshire, a prehistoric longhouse dating to 3,900BC was found. Then three others came to light. Across the River Dee from the first discovery at Balbridie, another longhouse was identified, then another at Claish Farm on the River Teith in Perthshire, and another near Kelso on the Tweed. Farming had crossed the North Sea and arrived in Scotland.

Geneticists have detected a movement of women, of mitochondrial DNA (mtDNA) markers, in the same period. Studies of mtDNA have tracked markers such as mtDNAJ2al and J1b1 arriving in the 5th and 4th millennia BC by two routes, the Atlantic littoral and along Europe’s great river valleys. And there are indications that a third and fourth, T1a and K2a, came to Scotland at around the same time.

Together these four lineages account for about 10 per cent of the modern female population of Scotland. Research carried out on female skeletons found at the sites of LBK communities of farmers in Germany and Hungary has identified another marker, N1a, which is now very rare, present in only 0.2 per cent of all European women. It is found in Scotland, and there is an extremely close match with a lady from East Lothian farming stock. She is probably a direct descendant of one of the LBK skeletons and the latest in a very long line of farmers.

Until the advent of mechanisation in the 20th century, the more menial, day-in-day-out jobs on farms were done by women. Hoeing, milking and anything not associated with horses, carting or ploughing was the province of many generations of female farm workers.

It may well be that prehistoric farming skills travelled across Europe in the movement of women, whether traded or as marriage partners. A woman able to manage the milking of ewes, goats or cows would have added value, and it may well be that the diversity of mtDNA and the diffusion of farming across Europe are linked.

As Scotland’s history emerged from the mists of prehistory and was first recorded, almost always by outsiders, evidence of warfare, conquest and population movement can be found. Running alongside DNA research, written and archaeological sources for our national story often combine to make a more complete picture. And sometimes mysteries are solved. For example, what happened to the exotic, enigmatic culture of the Picts? DNA supplies some answers.

• The Scots: A Genetic Journey by Alistair Moffat and Dr Jim Wilson is published on Saturday. Readers of The Scotsman and Scotland on Sunday can buy copies of the book at the special price of £12.75 (p&p free in the UK) by calling 7 and quoting reference SMAN211

• In a programme of pioneering research at Edinburgh University, Dr Jim Wilson has been gathering samples of DNA from Scots across the country and this week, in a new book by Alistair Moffat, and in a series of features in The Scotsman, we discover what his innovative work has revealed – and where the Scots came from. DNA – deoxyribonucleic acid – is the basis of life. Its molecular structure was discovered in 1953, revealing how it carries all the genetic information needed for organisms to live and reproduce. Scientists describe it in sequences of letters, and humans inherit three billion from each of their parents. As generations move from place to place, distinctive DNA markers are carried by each and every one of us. Day 2 of our series looks at the men who have literally left their mark on history

A Stuart with connections to an Irish crown

• DESPITE bearing two quintessentially Highland names, retired fisherman Lachlan Stuart is descended from Niall Noigiallach, the great and fecund High King of Ireland. Stuart, 59, carries Noigiallach’s marker, M222 and he is not alone, sharing it with 150,000 Scotsmen and more than half a million Irishmen.

• The Stuart family has moved away from the traditional territories of Dalriada in the west and south-west Highlands and Islands and Lachlan’s more recent ancestors hail from Grantown-on-Spey while he himself has moved further east to Keig in Aberdeenshire.

• “It’s really something special, isn’t it?” was Lachlan’s delighted reaction to his DNA results – even though they overturned his preconceptions and family stories.

• “I always thought I would have been descended from the Picts. And we can trace our family back to Stuart of Duffus, near Elgin, in the 1750s and I’d been told by my grandparents that we were of the Stewart of Appin line.

• “One the earliest of my ancestors to be mentioned was at Culloden, and he was a smallholder, Stuart of Croftmore, a mile from Duffus. I had also wondered if we were descended from the Wolf of Badenoch (the lawless warlord who burned Elgin Cathedral) given that he came from nearby and his family had many Alexanders and Lachlans over the last 250 years.”

• Alexander Stewart was the Wolf of Badenoch’s name and he was the brother of James III, King of Scotland. Lachlan Stuart’s instincts about his royal connections were correct – he just had the wrong royal family.

NAMES tell stories. And few are more fascinating than the story of the name of Britain. It was probably coined by a Greek traveller some time around 320BC. Pytheas made an epic journey to these islands, the earliest recorded to come down to us.
Having left his home city of Massalia, modern Marseilles, he may have travelled overland to the headwaters of the Garonne and then downriver to the Bay of Biscay. Amongst other things, tin was what interested Greek merchants, for it was an essential admixture to the alloy known as bronze, and there were islands in the northern sea where it was mined and smelted. But no-one had ever been there. When Pytheas eventually reached the southern shores of the Channel, perhaps somewhere near Calais, he looked across at the distant shimmer of the white cliffs and asked a question. “What are these people called, those who live across the narrow sea?”

Pretannikai was how he wrote down the answer, and the island was called Pretannike. By the time Julius Caesar’s legions splashed onshore in 55BC, the name had changed a little from the Greek to become Britannia in Latin. And it stuck.

“Britain” is so much part of the way we think about the world that we rarely consider it might mean something, literally. And that it might have something important to say about the beginnings of our own history, about who the peoples of the island were and what they looked like.

Pretannikai means “The Tattooed People”, and Britain means the Island of the Tattooed People. It was such a distinctive cultural characteristic for the early peoples of Britain to decorate their bodies that those who lived to the south thought it defining and they conferred the name. This most perishable artform, of course, died with the people who made it, but some sense of what the early British looked like and why they decorated their bodies has survived in the archaeology of the north of Scotland.

In AD235 a minor civil servant known as Herodian wrote a history of the Roman Empire. Amongst the most savage of the peoples pressing on the imperial frontier were a group to the north of the province of Britannia, the inhabitants of part of what is now Scotland. Apparently they were famous for tattooing their bodies not only with the likenesses of animals of all kinds but with all sorts of drawings. So that they did not hide their tattoos, Herodian insisted that these warriors did not wear clothes. They must have been hardy as well as colourful.

By AD297 Roman commentators were talking of a people they called the Picts, and for a century their raiding parties were to cross Hadrian’s Wall, sometimes reducing the province of Britannia to chaos. Writing after the collapse of the Western Empire in the 5th century, Isidore of Seville not only gave details of how the Picts applied their tattoos but also related the designs to personal rank, their painted limbs being marked to show their high birth.

Surprisingly, some of these marks or designs appear to have survived. The Picts left little or no literary evidence of their culture and history and few other material remains have come to light. But one dazzling phenomenon does stand testament in the landscape. Their great symbol-stones remember the Pictish centuries in the north of Scotland, and they tell a rich story. Two hundred stones have survived, almost certainly a small fraction of the original number. They may have been used as boundary markers, memorials or simply as expressions of personal prestige. The earliest group are known as Class I and, pre-Christian, they date to the time before AD600. Many carry mysterious, abstract symbols as well as representations of animals. Following Isidore’s observations, these may well have been tattooed on the bodies of individuals and were full of significant, possibly religious meaning.

Many cultures have used animals as totems, and early Roman maps listed peoples in northern Scotland with suggestive names. The Epidii in Kintyre translate as the Horse Kindred, the Venicones of Fife were the Kindred Hounds, the Lugi in Sutherland were the Raven People and the Orcades in Orkney, the Wild Boar People. Birds, horses, boars and other animals appear on the symbol stones and, at Burghhead on the southern shore of the Moray Firth, the old Pictish naval fortress seemed to be dedicated to a bull cult. Thirty carvings of bulls were found on the site, although only six now survive. There were other echoes around the firth. Roman mapmakers plotted a coastal fortification called Tarvedunum, the Bull Fort, and Thurso translates as “Bull’s Water”. This version of geography is a powerful reminder of the role of native animals as well as people in shaping a vivid sense of the identities of early Scotland.

At its zenith in the 7th century Pictland stretched from the northern shores of the Forth up the eastern coastlands to Caithness, on to Orkney and Shetland and across the Highland massif to Skye and the Outer Hebrides. The symbol stones show kings and aristocrats, battle scenes and ranks of soldiers, animals real and fantastical, gorgeous decoration and the enigmatic designs that may have been badges of rank. Pictland oozed prestige and power. When the English-speaking kings of Northumbria threatened to overrun the north, they were stopped dead in their tracks at Dunnichen, near Forfar. In 685 a Pictish army cut them to pieces in an ambush and killed the Northumbrian king. But by the early 9th century the confident society shown on the symbol stones was fading.

In AD839 a fateful battle was fought in Strathearn, many Pictish aristocrats were killed and within a generation their power was becoming a memory. The Vikings had sailed into history and it seems that at Strathearn their elemental savagery all but extinguished a culture. The language of the Picts, that of most of the north of Scotland, was silenced, and since no written records survive, it is impossible to reconstruct. All that remain are a few names and words for geographical features. No-one now can utter a sentence in Pictish.
What happened to these people and their language, culture and political power? Were they massacred, driven off their land into starvation and extinction or simply submerged into other dominant groups? Where did the Picts go?

Nowhere. DNA studies are unequivocal. The Picts are alive, well and living quietly among us. Their distinctive DNA marker has been identified and is one of the very few to have been given a name. S145-Pict is carried by 7 per cent of Scottish men, 175,000 in all, and its distribution is wide, extending over much of the north of Scotland, over ancient Pictland. In the seven traditional provinces of Angus and the Mearns, Atholl and Gowrie, Strathearn and Menteith, Fife and Kinross, Marr and Buchan, Moray and Easter Ross and Caithness and south-east Sutherland, most carriers were clustered. More than that, it was in these areas that most mutations of the marker had taken place, and therefore it had certainly originated in the Pictish provinces of northern and eastern Scotland.

It also turns out that Pictish kings and noblemen did not all perish at Strathearn and some lineages appear to have carried on – but under assumed names. The owners of clan names are especially enthusiastic about tracing their genealogy and having their DNA analysed.

Clan MacGregor has a colourful record, with men like Rob Roy and Sir Gregor MacGregor making slightly disreputable but dashing marks on history. Their clan lands were in Perthshire, on the eastern slopes of the Drumalban Mountains, firmly in the ancient domain of the Picts. From a sample of 144 MacGregor Y chromosomes, a large proportion, 53 per cent, clearly descend from one individual. The clan motto is “S Rioghal mo Dhream”, my race is royal. They claim lineage from Alpin, the ancestor of Kenneth MacAlpin, king of Dalriada and Pictland in the mid-9th century and the king of Scotland from whom all successive monarchs are numbered.

The problem with the tradition is that MacAlpin’s DNA was almost certainly Irish/Celtic, and that of the 53 per cent of the MacGregors who share a common ancestor is not. They all carry S145-Pict. Whoever Gregor was, he is unlikely to have been a Dalriadan. And with 53 per cent of the total sample being Pictish compared with only 7 per cent of the Scottish population, the clan is emphatically Pictish and possibly descended from royalty. But perhaps not the royalty they had in mind. More surprises have cropped up to the west of MacGregor country. Another large lineage cluster in the extensive sample of men with the name of MacDonald has a very different origin. They are not branches of the lineage that stemmed from the first Lord of the Isles, Somerled the Viking. Around 12 per cent of MacDonalds carry the classic S145-Pict marker and it may be that they are descended from a powerful individual whose identity is now lost but who chose to join with Clan Donald and adopt the name. There are two mainland branches: MacDonell of Glengarry and Clan Ranald. Both have chiefs with the Somerled marker but their followers may well be Pictish.

Nevertheless, the carriers of S145-Pict may console themselves with a simple fact. Their kings and aristocracy may have largely fallen, but the surviving lineages are amongst the oldest in Scotland. And even if they no longer tattoo their bodies, they can fairly claim to be the last of the British. The victors of the battle in Strathearn were unquestionably ferocious and determined warriors, and in many ways the 9th century in Britain was the Viking century. But one aspect of their legacy is surprising. Despite the trail of savagery and gore, or perhaps because of it, most Scottish men asked about their DNA before being tested appear to want it to show descent from the terrifying Vikings.

Our series on the DNA make-up of Scots looks at how the Vikings left an indelible mark on this country and in particular Orkney, where around 20 per cent of all Orcadian men carry the bloodthirsty raiders’ M17 marker
HIDDEN snug beneath oiled sheep- and goatskins, or tucked into tiny corners under gear, or nibbling at parcels of food, mice began sailing to Scotland in the 9th century. They came from Norway, mostly, and settled in Orkney, where their descendants still thrive. The mice brought other creatures with them who were neither tim’rous nor cow’rin, but they were certainly beasties. The mice sailed the North Sea with the Vikings.DNA researchers conducted a series of tests on house mice in Orkney and discovered that their genetic make-up was quite different from mice on the Scottish mainland, even though they had been on the islands for about 1,000 years. But when they compared it with that of mice in Norway, they found it was an exact match. The only possible explanation was that mice had stowed away on Viking longships and when these ferocious warriors rasped up their keels on Orcadian beaches to attack terrified communities, their little passengers quietly scuttled through the rocks and seaweed to settle and multiply.

As with mice, so it was with men. The Viking attacks began in AD793 with the surprise assault on the Holy Island of Lindisfarne. Even across 12 centuries the shock is palpable. These pagan sea-raiders seemed to sail out of nowhere and attack without hesitation some of the most sacred places in the north. The footsteps of Columba and Cuthbert were spattered with blood as monks and nuns were tortured, killed and raped, and their churches echoed not with prayer and plainsong but with the screams of the dying as they were ransacked for gold, silver and other valuables. Iona was desecrated repeatedly.

An account of what happened in AD825 was written by Walafrid Strabo, Abbot of Reichenau in southern Germany. Like many raiders wishing to use the element of surprise, the Vikings attacked the monastery on Iona at first light and broke into the abbey where St Blathmac and his followers lay prostrate in prayer. In what must have been a terrible orgy of ferocity, they were all slaughtered before the altar except for their leader. Demanding to know where the monks had buried Columba’s reliquary and other precious objects, the Vikings began to torture Blathmac. Using ponies they took ropes attached to their harness and tied the ends to his arms and legs, and when he continued to refuse to give up the holy relics, Walafrid wrote that the pious sacrifice was torn limb from limb.

The appalling fate of Blathmac was by no means unique. Among recorded atrocities – and there must have many that were not – the pagan ritual of blood-eagling was horrific. As a sacrifice to the war god, Odin, victims were tied face-first to a post or pillar before a Viking marked the blood-eagle on his back. In AD869 King Edmund of East Anglia suffered this dreadful death when his ribs were hacked from his spine and pulled outwards like an eagle’s wings. Then his lungs were wrenched out and draped over his shoulders. On Orkney the Viking Earl Turf Einarr ordered the same ritual in the 870s. It is no wonder the monks called the Vikings the Sons of Death.

In the light of such sustained and well-documented barbarity it is perhaps surprising that many Scottish men hanker after a Viking legacy. Before having their DNA tested, they often express a wish to be the descendants of these bloodthirsty raiders and many are disappointed when another result is conveyed. But there is a significant group who glory in the DNA of the Vikings, and while there was much to abhor, it is fair to say that there was also much to admire. Great seamen and daring, they sailed in open longships to discover Iceland, Greenland, (eventually making landfall in North America), they founded the embryonic Russian state of Kievan Rus, composed epic sagas of verve and colour, and inspired the cartoon character Noggin the Nog – although his mild manners must have been an exception.

Recent DNA research has shown a very significant Viking inheritance in Orkney. Around 20 per cent of all Orcadian men carry the M17 marker, the classic signature of Viking settlement. If the statistics are narrowed to cover only men with ancient Orcadian surnames like Linklater, Foubister, Clouston, Flett or Rendall, the percentage of M17 rockets to 75 per cent.

M17 is also present in the Western Isles in large numbers. Clan names are a visible relic; MacIvors were originally the sons of Ivar, MacSween, the sons of Swein, Macaulay, the sons of Olaf, MacAskill, the sons of Asgeir and so on. Clan MacLeod is a fascinating case study. From a sample of the DNA of 45 Macleod Y chromosomes almost half, 47 per cent, clearly show social selection at work in that they descend from one individual. If this statistic is projected amongst the total number of MacLeods, it means that almost 10,000 men alive today are descended from this man. Among the remaining 53 per cent, researchers have found only nine other lineages present, showing that MacLeod men married women who were unfailingly faithful to them.

Nevertheless, the MacLeods do not carry the M17 marker group. Theirs is a recently discovered sub-group labelled S68. It is found in Lewis, Harris and Skye, core Macleod territory, but also in Orkney, Shetland and Norway, with a few examples in Sweden. Despite extensive screening, S68 is very specifically located, showing up only once in the east of Scotland and once in England. This is a classic pattern for a Viking marker in Britain, but one much rarer than M17. MacLeods determinedly claim descent from a common name father, a Norse aristocrat called Ljot, a relative of Olaf, King of Man. They are probably right to continue to claim that – science for once supporting tradition.

Despite striking examples of extreme violence, the Vikings were often anxious to keep their captives alive. At Dublin they set up a great slave market and many poor souls were sold on to the agents of wealthy individuals. Some were taken as far south as the Mediterranean and the developing Muslim states of Spain and North Africa where fair-skinned thralls or slaves commanded a premium. The discovery of both the pan-British Isles DNA marker of S145 and the Irish and Scottish-specific M222 in coastal Norway has suggested a remnant legacy of slaves shipped back to the Viking homeland. Even very small numbers of M284, one of the founding lineages in Scotland, have been detected. Although many Scots visited and even settled for long periods in Norway, from the later middle ages onwards, it is quite possible that some of these S145 and M222 descendants are, in fact, the children of slaves. The British-specific mtDNA or female group of J1b1 has also been found in coastal Norway, and it almost certainly represents another survival of slaving.

There is a fourth distinctly Irish subtype of the great S145 marker but, like the Pictish subgroup, it has yet to be identified with a single, slowly evolving marker. Instead geneticists rely on a particular signature of more quickly evolving markers to identify members of this group. It is concentrated in Munster, and particularly in counties Cork and Kerry. It is very rare in Scotland and has only been found in the Northern and Western Isles. This suggests that it is unlikely to have spread outwards from Dalriada – as M222 appears to have done. Rather it looks as it was taken directly from South-west Ireland to north and west Scotland. A likely explanation would be that these lineages represent the descendants of Irish slaves taken north by the Vikings. This is supported by the fact that the major genetic lineage of the surname of Macaulay, the sons of Olaf, belongs to the group. It seems that some slaves contributed to the ancestral gene pool of the peripheral regions of Scotland.

One of the most fascinating mixes of DNA in Scotland can be seen in the most southerly part of the country. The territory of Greater Galloway stretched east to Annandale and north to include Carrick and it may be seen as a palimpsest of our linguistic and cultural history, a mirror to what happened in perhaps more familiar parts of the country. The most westerly peninsula, the Rhinns of Galloway, lies close to Ireland and at the same time as Dalriada was emerging in Argyll and the south-western Hebrides, Gaelic was certainly also spoken there. The ancient kingdom of Rheged understood itself in Old Welsh and it had royal centres near Stranraer, Kirkcudbright and probably at Carlisle. When it faded and died at the end of the 6th century, the English-speaking Bernicians pushed westwards to establish an episcopal see at Whithorn and colonise fertile costal areas.

Even Pictish became part of the mix – by mistake. The Bernicians may have believed the Gaelic speakers of Galloway to have been Picts because the first two bishops at Whithorn took symbolic names. Peohthelm means “Leader of the Picts” and Peohtwine “Friend of the Picts”.

In the late 9th and early 10th century the kaleidoscope was twisted once more when some of the Celto-Norse peoples of the Hebrides migrated south. Because they spoke Gaelic but were descended from Vikings, they became known as the Gall-Gaidheil and they gave their name to Galloway.

It means the Land of the Stranger-Gaels. For six centuries at least, dialects of Old Welsh, Gaelic and English were spoken by substantial communities who lived alongside each other.

Multiculturalism may not be fashionable in certain quarters nowadays but it has a long history in Scotland. A very early linguistic mix like this is usually reflected in DNA, and when more testing is completed in Galloway, a rich and complex picture is likely to emerge.

Perhaps the most attractive achievement of the Viking settlers and their descendants was the great medieval Atlantic principality of the west, the Lordship of the Isles. It was essentially the creation of Somerled, also the founder of Clan Donald and the progenitor of its major name-fathers. There is accurate data available from a large sample, from 164 MacDonald Y chromosomes, and they contain a fascinating twist on tradition.

Somerled was known to chroniclers as Somerled the Viking and it turns out that the large number in the sample descended directly from him, 23 per cent, carry a specific signature type within the Norse subgroup of M17.

Somerled’s own ancestors did indeed originate in Scandinavia. And the tradition lives on, for Clan Donald have genotyped the chiefs of their various clan branches and they all carry the old Vikings’ marker.

It seems in the north, west and south of Scotland the legacy of the sea-raiders carries on. Most of the significant in-migrations to Scotland had taken place by the years around AD1000, but in the later 19th and the 20th century, the age of mass transport, more peoples came to enrich our collective DNA.